Magnetic sensor systems are increasingly important in a variety of industries. For example, accurate rotational speed measurement is a vital component in maintaining performance, safety, and reliability in modern vehicles. It forms the basis of numerous applications from anti-lock braking to engine management systems, and provides means for embedding intelligence throughout a vehicle via advanced networks and control systems. Accordingly, modern vehicles are increasingly being equipped with magnetic sensors to monitor the speed of a crankshaft or camshaft, to monitor a rotation speed of a wheel about a wheel axis in an anti-lock braking system (ABS), and so forth. Such magnetic sensors (also referred to as speed sensors, angular sensors, and/or rotational sensors) may help increase vehicle stability, reduce vehicle emissions, and enable drive-independent control functions.
In general, a magnetic speed sensor is configured to sense the motion of a magnetic encoder gear wheel or a magnetized target. A periodic magnetic field stemming from the effect of flux bending by the magnetic gear wheel or directly from the magnetized target is transformed by the magnetic speed sensor into an analog electrical signal. The frequency of the signal is proportional to the rotational speed of the target. Different sensor applications may have different restrictions regarding the size and shape of a sensor package in order to allow the sensor to be mounted as close as necessary to a target to be measured. Additionally, among other design and performance considerations, such magnetic speed sensors are typically required to fulfill electromagnetic compatibility (EMC) and electrostatic discharge (ESD) performance requirements.